The Square Kilometre Array: A new probe of cosmic magnetism

Abstract

Magnetic fields are a fundamental part of many astrophysical phenomena, but the evolution, structure and origin of magnetic fields are still unresolved problems in physics and astrophysics. When and how were the first fields generated? Are present-day magnetic fields the result of standard dynamo action, or do they represent rapid or recent field amplification through other processes? What role do magnetic fields play in turbulence, cosmic ray acceleration and structure formation? I explain how the Square Kilometre Array (SKA), a next-generation radio telescope, can deliver stunning new data-sets that will address these currently unanswered issues. The foundation for these experiments will be an all-sky survey of rotation measures, in which Faraday rotation toward >10^7 background sources will provide a dense grid for probing magnetism in the Milky Way, nearby galaxies, and in distant galaxies, clusters and protogalaxies. Using these data, we can map out the evolution of magnetized structures from redshifts z > 3 to the present, can distinguish between different origins for seed magnetic fields in galaxies, and can develop a detailed model of the magnetic field geometry of the intergalactic medium and of the overall Universe. In addition, the SKA will certainly discover new magnetic phenomena beyond what we can currently predict or imagine.

arXiv comment8 pages, 3 embedded figures, 1 jpeg figure. To appear in special issue of Astronomische Nachrichten, "The Origin and Evolution of Cosmic Magnetism", eds. R. Beck et al

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Cited by in corpus (10)

• Cosmological Magnetic Fields: Their Generation, Evolution and Observation
• On the Origin of Cosmic Magnetic Fields
• Non-Gaussian features of primordial magnetic fields in power-law inflation
• Probing magnetic turbulence by synchrotron polarimetry: statistics and structure of magnetic fields from Stokes correlators
• Cosmological Simulations using GCMHD+
• Cherenkov Telescope Array sensitivity to branon dark matter models
• Thermal Evaporation of Gas from X-ray Clusters
• Magnetizing the universe
• Revisiting primordial magnetic fields through 21-cm physics: Bounds and forecasts
• Magnetic fields in galaxies: I. Radio disks in local late-type galaxies